Coupling with tongue and groove

ABSTRACT

A coupling includes an annular gasket, the annular gasket including at least one sealing surface directed radially inwardly and an outer surface directed radially outwardly; at least one segment, each segment being approximately semi-circular and including at least one inner surface, at least one outer surface, and at least two ends, each segment including a fastener pad protruding proximate to each end, each fastener pad defining a fastener hole, each end including at least one of a tongue and a groove, each tongue protruding circumferentially from at least one end, each groove defined circumferentially in at least one end; and at least one fastener, wherein at least one portion of a shaft portion of the fastener is sized to engage at least one fastener hole in at least one segment.

FIELD

This disclosure relates to piping. More specifically, this disclosurerelates to pipe coupling.

BACKGROUND

Pipe elements such as pipes, valves, and meters typically are not madeof one piece. Rather, such pipe elements are formed in finite lengthsand must be joined. One way of joining such pipe elements is through theuse of a coupling member. A sealing gasket is typically disposed in acentral space of at least one coupling segment which is thereaftertightened around the pipe elements to be joined.

SUMMARY

A coupling is disclosed including an annular gasket, the annular gasketincluding at least one sealing surface directed radially inwardly and anouter surface directed radially outwardly; at least one segment, eachsegment being approximately semi-circular and including at least oneinner surface, at least one outer surface, and at least two ends, eachsegment including a fastener pad protruding proximate to each end, eachfastener pad defining a fastener hole, each end including at least oneof a tongue and a groove, each tongue protruding circumferentially fromat least one end, each groove defined circumferentially in at least oneend; and at least one fastener, wherein at least one portion of a shaftportion of the fastener is sized to engage at least one fastener hole inat least one segment.

Various implementations described in the present disclosure may includeadditional systems, methods, features, and advantages, which may notnecessarily be expressly disclosed herein but will be apparent to one ofordinary skill in the art upon examination of the following detaileddescription and accompanying drawings. It is intended that all suchsystems, methods, features, and advantages be included within thepresent disclosure and protected by the accompanying claims.

DESCRIPTION OF THE FIGURES

The features and components of the following figures are illustrated toemphasize the general principles of the present disclosure and are notnecessarily drawn to scale. Corresponding features and componentsthroughout the figures may be designated by matching referencecharacters for the sake of consistency and clarity.

FIG. 1 is an exploded perspective view of a coupling in accord with oneembodiment of the current disclosure.

FIG. 2 is an outer perspective view of a segment of the coupling of FIG.1.

FIG. 3 is an inner perspective view of the segment of FIG. 2.

FIG. 4 is a cross-sectional view of the segment of FIG. 2.

FIG. 5 is a cross-sectional view of a gasket of the coupling of FIG. 1.

FIG. 6 is a side view of the coupling of FIG. 1 in an assembled anduntightened position.

FIG. 7 is a side view of the coupling of FIG. 1 in an assembled andtightened position, including a cross-sectional view of pipe elements.

FIG. 8A is a cross-sectional view of the coupling of FIG. 1 beforeinstallation on pipe elements.

FIG. 8B is a cross-sectional view of the coupling of FIG. 1 duringinstallation on pipe elements.

FIG. 8C is a cross-sectional view of the coupling of FIG. 1 duringinstallation on pipe elements.

FIG. 8D is a cross-sectional view of the coupling of FIG. 1 duringinstallation on pipe elements.

FIG. 8E is a cross-sectional view of the coupling of FIG. 1 afterinstallation on pipe elements.

FIG. 9 is a cross-sectional view of the coupling taken in a planeindicated by line 9 in FIG. 6.

FIG. 10 is a partial cross-sectional view of the coupling of FIG. 1assembled around pipe elements and in an untightened position.

FIG. 11 is a partial cross-sectional view of the coupling of FIG. 1assembled around pipe elements and in a tightened position.

DETAILED DESCRIPTION

Disclosed is a pipe coupling and associated methods, systems, devices,and various apparatus. The pipe coupling includes at least one segment,at least one tightening element, and at least one gasket. The pipecoupling is adapted to seal pipe elements in end-to-end relationship. Itwould be understood by one of skill in the art that the disclosed pipecoupling is described in but a few exemplary embodiments among many. Noparticular terminology or description should be considered limiting onthe disclosure or the scope of any claims issuing therefrom.

One embodiment of a pipe coupling 100 is disclosed and described inFIG. 1. The pipe coupling 100 of the current embodiment includes twosegments 110,110′ although any number of segments 110 may be used invarious embodiments. The current embodiment includes tightening elementsor fasteners that are nut and bolt fasteners. Two bolts 120 a,b aredisposed to interact with nuts 125 a,b in threaded engagement. Varioustypes of tightening elements may be used in various embodiments, and thedisclosure of bolts 120 a,b, and nuts 125 a,b should not be consideredlimiting. Fastener pads 130 a,b protrude from segment 110 and fastenerpads 130 a′,b′ protrude from segment 110′. Fastener holes 132 a,b,a′,b′are defined in fastener pads 130 a,b,a′,b′, respectively. In the currentembodiment, the fastener holes 132 a,b,a′,b′ are about centered withinthe fastener pads 130 a,b,a′,b′, although they may be offset in variousembodiments. Although the fastener pads 130 a,b,a′,b′ and fastener holes132 a,b,a′,b′ are described in the current configuration, variouslocations and configurations of fastener pads 130 a,b,a′,b′ and fastenerholes 132 a,b,a′,b′ are included in various embodiments. A gasket 150 isincluded with the pipe coupling 100. The gasket 150 of the currentembodiment is annular and adapted to surround and to seal fluid piping,although various configurations will be included in various embodiments.

FIGS. 2, 3, and 4 show segment 110. In the current embodiment, segment110′ is substantially identical to segment 110. As seen in FIG. 2, eachsegment 110 includes two ends 203,207 and a segment body 210 disposedbetween the two ends 203,207. Each segment 110 in the current embodimentis about semicircular, although other configurations may be used invarious embodiments. Proximate each end 203,207 is a shoulder 213,217protruding outwardly from the segment 110. Each shoulder 213,217provides a connection point for a fastener which, in the currentembodiment, is a bolt 120. Each shoulder 213,217 includes fastener holes132 a,b defined in fastener pads 130 a,b.

Each segment body 210 includes a central portion 215 and at least oneedge portion 225 b (225 a not shown in FIG. 2). In the currentembodiment, the edge portions 225 a,b are designed to interact with agroove in the pipe elements to be sealed and joined, although someembodiments may be designed to interact with non-grooved pipe elements.

As can be seen in FIG. 2, each fastener hole 132 a,b includes a firstlinear extent or an axial length 233,237 and a second linear extent ortransverse length 243,247. The axial lengths 233,237 and the transverselengths 243,247 are measured at top surfaces 364,314 of the fastenerpads 130 a,b. These dimensions increase through the fastener pads 130a,b in the current embodiment because they are cast, and a draft angleis used in casting. In various embodiments, these dimensions may remainconstant if, for example, the fastener holes 132 a,b are made via amachining step. In the current embodiment, each fastener hole 132 a,b isabout ovular in shape, although other embodiments may include variousshapes. The shape of the current embodiment of the fastener holes 132a,b provides interference with the bolts 120 a,b to reduce rockingmotion, as will be described later with reference to FIG. 9. Eachsegment 110 includes an outer surface 250 and an inner surface 260. Acontact surface 262 b (262 a shown in FIG. 3) is included on the insideof each edge portion 225 a,b. Also seen in FIG. 2 is a tongue 280, aswill be described in more detail with reference to FIGS. 3, 4, and 6.

As seen more clearly in FIG. 3, the tongue 280 protrudes from the end207 of the segment 110.

The shoulder 217 can be seen protruding outwardly from the segment 110.In the current embodiment, the shoulder 217 includes a bottom surface312 and a top surface 314. The bottom surface 312 and the top surface314 are substantially parallel in the current embodiment and are angledin order to ensure proper alignment upon deformable tightening of thepipe coupling 100, as will be discussed later with reference to FIG. 4.However, in some embodiments, the bottom surface 312 and the top surface314 are not angled. A wall 317 of the shoulder 217 is seen along theoutside of the shoulder 217. The wall 317 in the current embodimentdefines a draft portion 316 having a draft angle such that the thicknessof the shoulder 217 at a beginning of the draft 318 is thicker than thethickness at an end of the draft 319. The angle of the draft portion 316is consistent between the beginning of the draft 318 and the end of thedraft 319 so that the region defining the draft angle is a linear taperin the current embodiment, although other shapes may be used in variousembodiments. A radiused portion 321 extends beyond the draft portion 316to provide an end 334 of the shoulder 217 beyond the fastener hole 132b. The wall 317 includes an outer surface 322.

As can be seen from the view of FIG. 3, the shoulder 217 includes ataper portion 326. The taper portion 326 terminates at the end 334 ofthe shoulder 217 and melds at the other end with a parallel portion 327of the shoulder 217. As previously described, the bottom surface 312 isparallel to the top surface 314 in the parallel portion 327. A ledgesurface 331 a,b provides a quick transition to the taper portion 326,which includes a taper bottom surface 332 that is not parallel to thetop surface 314. An inner surface 335 b of the fastener hole 132 b canalso be seen in the current view.

The tongue 280 includes three portions in the current embodiment: acentral portion 342, a first side portion 344, and a second side portion346. The side portions 344,346 are oriented with respect to the centralportion 342 such that an angle is formed between each. In the currentembodiment, the angle is greater than ninety degrees. The tongue 280includes an outer surface 352, an inner surface 354, and a matingsurface 355. The mating surface 355 is angled at a tip angle 430, whichis shown in FIG. 4. The mating surface 355 is located on a leading edgeof the tongue 280.

Shown along the other end 203 is the other shoulder 213. The shoulderincludes a bottom surface 362 and a top surface 364 that aresubstantially parallel. The shoulder 213 includes a draft portion 366and a radiused portion 371. A taper portion 376 is included just likewith shoulder 203. A parallel portion 377 is also included where thebottom surface 362 is parallel to the top surface 364 in the region.Ledge surfaces 381 a,b (not shown) are also included just like ledgesurfaces 331 a,b, and a taper bottom surface 382 is also included.

A groove 380 is defined in the shoulder 213. The groove 380 is sized toaccept the tongue 280. The groove 380 includes a central wall 392 andtwo side walls 394,396. The groove 380 is further defined by a matingsurface 395. In assembly, the mating surface 395 contacts the matingsurface 355′ of another segment 110′. A groove shoulder surface 389 isincluded on the inside of the groove 380. A draft portion 388 can beseen proximate the end of the segment 110 nearest the groove 380. Thedraft portion 388 provides a relief from the inner surface 260 to themating surface 395 to line up with the tongue 280′, which is slightlyset back from the inner surface 260′. The draft portion 388 helpsprevent the coupling 100 from pinching the gasket 150 duringinstallation, as pinching of the gasket 150 can lead to failure of thegasket 150 including slicing and rupture of the gasket 150. A draftportion shoulder surface 387 a,b (387 b not shown) provides the part ofthe step-down from a shoulder surface 296 a,b (296 b not shown) to themating surface 395.

Each edge portion 225 a,b of the segment 110 includes a contactingportion 292 a,b and a support portion 294 a,b. The contact surface 262a,b is included at the end of the contacting portion 292 a,b. Theshoulder surface 29 a (296 b not shown) can be seen at the inside end ofthe support portion 294 a (inside end of the support portion 294 b notshown). Three nodes 297 a,298 a (299 a,b and 297 b,298 b not shown)protrude from the shoulder surface 296 a,b between the support portion294 a,b and the contacting portion 292 a,b. Each node 297 a,b and 298a,b include a width that decreases from the support portion 294 a,b tothe contacting portion 292 a,b. Although the nodes 297 a,b, 298 a,b, and299 a,b are pyramidal in the current embodiment, they may be variousshapes in various embodiments.

The gasket 150 is designed to interact with the inner surface 260 ofeach segment 110 in the pipe coupling 100, as will be discussed withreference to FIG. 5.

As seen in the cross-sectional view of FIG. 4, the top surfaces 314,364and the bottom surfaces 312,362 are aligned at angles 415,416,417,418with respect to a horizontal axis 420 of the segment 110. A verticalaxis 425 is shown for reference. The angles 415,416,417,418 allow fordeflection of the segment 110 in use. In some embodiments, the angles415,416,417,418 will be zero such that the top surfaces 314,364 arealigned with the horizontal axis 420 when no deflection is present. Thetip angle 430 of the tongue 280 can be seen such that the mating surface355 is aligned angularly with respect to the horizontal axis 420. Thetip angle 430 is greater than the other angles 415,416,417,418 in thecurrent embodiment, although other configurations may be found invarious embodiments. When the segment 110 is deflected, the matingsurface 355 contacts the mating surface 395 of another segment 110. Invarious embodiments, the tip angle 430 is approximately the same as theangles 415,417 of the top surface 314 and bottom surface 312,respectively.

Also seen in cross-sectional view, each fastener hole 132 a,b is draftedsuch that each fastener hole 132 a,b defines a cone-shaped void that isapproximately ovular in cross-section, although various cross-sectionalshapes may be found in various embodiments. As such, each fastener hole132 a,b includes a smaller aperture at the top surface 314,364 thanwhere the fastener hole 132 a,b emerges into the taper bottom surface332,382 and the bottom surface 312,362. This configuration may beomitted in various embodiments.

As can be seen in FIG. 5, the gasket 150 is ring-shaped and includes anannular body 510 having a radially outer surface 515. The radially outersurface 515 interacts with the inner surface 260 of each segment 110 inthe pipe coupling 100. The radially outer surface 515 of the annularbody 510 includes a deformation groove 517. The annular body 510includes side portions proximate axial ends of the annular body 510.Extending substantially radially inward from the side portions of theannular body 510 are a pair of sealing ribs 520 a,b. Each sealing rib520 a,b extends substantially radially inwardly and increases inthickness from radially outside to radially inside. Each sealing rib 520a,b also has an axially outer surface 521 a,b extending from theradially outer surface 515 to the start of an axially outer drafted edge522 a,b. Each axially outer surface 521 a,b is angled with respect to aradial direction. The angle of each axially outer surface 521 a,b isconsistent around the entirety of the annular body 510, so that axiallyouter surfaces 521 a,b are shaped as a truncated cone. In the currentembodiment, each axially outer surface 521,a,b is angled betweennineteen and twenty-two degrees with respect to a radius of the gasket150, although other configurations may be present in variousembodiments.

Each sealing rib 520 a,b has a sealing ridge 525 a,b extending axiallyinward from a radially inward end 551 a,b of each sealing rib 520 a,b.Each sealing ridge 525 a,b extends substantially axially inward from theradially inward end 551 a,b of each sealing rib 520 a,b, such that thetwo sealing ridges 525 a,b extend toward each other. The axially outerdrafted edges 522 a,b extend from the radially inward end 551 a,b to acontact portion 555 a,b. Each axially outer drafted edge 522 a,b may berounded, slanted, or various shapes in cross-section in variousembodiments. Such cross-sectional shapes translate to conical andparaboloid shapes in various embodiments. Such shapes are truncated, asa full cone or paraboloid would not allow insertion of pipe elements inthe gasket 150. In the embodiment shown in FIG. 5, the axially outerdrafted edges 522 a,b are slanted at an angle approximately between 27°and 28° from a radial direction, although various other angles may bepresent in various embodiments. Contact portions 555 a,b extend alongthe sealing ridges 525 a,b from the axially outer drafted edges 522 a,bto an axially inner drafted edge 527 a,b. Each contact portion 555 a,bincludes a sealing surface 526 a,b facing radially inward and coplanaror collinear with each other in the cross-sectional view. Thecoplanar/collinear arrangement in cross-sectional view denotes acoannular surface profile of the sealing surfaces 526 a,b in the currentembodiment, although the surfaces may be of different diameters invarious embodiments. The sealing surfaces 526 a,b are intended tocontact pipe elements placed inside of the gasket 150 to provide a fluidseal for the pipe elements. The sealing surfaces 526 a,b face radiallyinwardly and extend substantially axially at rest. In other words, by“face radially inwardly,” when the sealing surfaces 526 a,b are not incontact with pipe elements, the sealing surfaces 526 a,b approximate acylinder that is about coaxial with the pipe elements intended to beused with the coupling 100. Thus, the sealing surfaces 526 a,b appear aslines that are parallel with the axis of pipe elements 710 incross-sectional view, as seen in FIGS. 8A-8E. Any angle with respect tothe pipe elements 710 is minimal.

The orientation of the sealing surfaces 526 a,b is intended to ease theinsertion of pipe elements into contact with the sealing surfaces 526a,b of gasket 150. Extending from each sealing surface 526 a,b is theaxially inner drafted edge 527 a,b. The axially inner drafted edges 527a,b may be rounded, slanted, or various shapes in cross-section invarious embodiments. Such cross-sectional shapes translate to paraboloidand conical shapes in various embodiments. Such shapes are truncated, asa full cone or paraboloid would not allow insertion of pipe elements inthe gasket 150. The axially inner drafted edges 527 a,b define thetermination of the sealing ridge 525 a,b along the axially inwarddirection.

A center rib 530 extends radially inward from the annular body 510. Thecenter rib 530 includes a central groove 531 and two sealing members 557a,b which each include a sealing surface 532 a,b. Each sealing member557 a,b in the current embodiment is a rounded protrusion from thecentral groove 531. In various embodiments, various shapes andconfigurations of sealing members 557 a,b may be used, includingflattened shapes, combinations of protrusions, and unconnected surfaces,among others. The sealing surface 532 a,b is included on the sealingmember 557 a,b,respectively. The central groove 531 is positionedbetween the sealing surfaces 532 a,b such that the sealing surfaces 532a,b of the sealing members 557 a,b are capable of contacting the pipeelements and providing additional sealing interaction therewith.

Each sealing rib 520 a,b has an innermost radial extent as measured fromthe annular body 510. In addition, each sealing rib 520 a,b has an edgeradial extent as measured from the annular body 510 to an axiallyinnermost end of each of the axially inner drafted edges 527 a,b. Thecenter rib 530 has an innermost radial extent as measured from theannular body 510. The innermost radial extent of the center rib 530 iscloser to the annular body 510 than the innermost radial extent of eachof the pair of sealing ribs 520 a,b. Additionally, in the currentembodiment, the innermost radial extent of the center rib 530 is closerto the annular body 510 than the edge radial extent of each of the pairof sealing ribs 520 a,b. The innermost radial extent of the center rib530 may be as far from the annular body as, or farther from the annularbody 510 than, the edge radial extent of each of the pair of sealingribs 520 a,b in various embodiments. The innermost radial extent of thecenter rib 530 may also be equally as far from the annular body 510 asthe innermost radial extent of each of the pair of sealing ribs 520 a,bin various embodiments.

The gasket 150 may be made of rubber, plastic, cork, wood, metal,ceramic, polymer, elastomer, rosin, foam, any combination of theforegoing materials, or any material suitable for sealing two pipeelements joined in end-to-end relationship. “Pipe elements” may meanpipes, valves, meters, or any other piping joint suitable to be sealed.

The annular body 510, the sealing ribs 520 a,b, and the center rib 530define gasket channels 540 a,b as seen in FIG. 5. The gasket channels540 a,b are pockets into which fluid media may flow when the gasket 150is in use. The gasket channels 540 a,b are tubular channels in thecurrent embodiment but may be various shapes in various embodiments.When placed in sealing contact with an exterior surface of a pipeelement, the gasket channels 540 a,b allow some fluid pressure to aid insealing the sealing ridges 525 a,b against pipe elements, although suchuse is not necessary for successful sealing of the gasket 150. Thecenter rib 530 decreases in thickness from its radial outermost to itstermination radially inward.

In addition, when the gasket 150 is in use, the sealing members 557 a,band the groove 531 act to prevent substantial fluid media flow into thegasket channels 540 a,b. When placed in sealing contact with exteriorsurfaces of pipe elements, the sealing surfaces 532 a,b of the sealingmembers 557 a,b prevent substantial fluid media flow into gasketchannels 540 a,b, retaining fluid media flow in the groove 531. Thegasket, in alternative embodiments, may include a plurality of centerribs, each with at least one sealing member and at least one sealingsurface, which perform the same function as described above to preventsubstantial media flow into the gasket channels.

One problem that the center rib 530 can alleviate is the buildup offluids in the gasket channels 540 a,b. For example, in applicationswhere fluid media is water in cold temperature environments, preventingwater buildup in the gasket channels 540 a,b can lead to damage to thegasket 150 if the water freezes and, thereby, expands.

FIG. 6 shows the coupling 100 in an assembled but untightened position.It can be seen in this view that each top surface 314,314′ is parallelto each bottom surface 312,312′, respectively. Likewise, each topsurface 364,364′ is parallel to each bottom surface 362,362′,respectively. However, the fastener pads 130 a,b,a′,b′ are not aligned.In other words, the surfaces of adjacent fastener pads 130 a,b,a′,b′ arenot parallel. As can be seen, top surface 314 is not parallel to topsurface 364 because angles 415 and 416 do not align. This angularmisalignment allows each segment 110,110′ to deflect under tighteningpressure of the bolts 120 a,b and nuts 125 a,b to provide so that thetop surfaces 314,314′ and 364,364′ are substantially parallel when thesegments 110,110′ are deformed. In various embodiments, the top surfaces314,314′ and 364,364′ may be parallel before deforming the segments110,110′. In such embodiments, the top surfaces 314,314′ and 364,364′may be non-parallel after deflection.

As can be seen in FIG. 6, the groove shoulder surface 389 of segment110′ is angled so that it aligns with an outer surface 352′ of tongue280′ of segment 110′ upon deformation of the segments 110,110′ as willbe shown below in FIG. 7. Upon deformation of the segments 110,110′ (asdescribed below), the grooved shoulder surface 389 of segment 110becomes parallel and flush with outer surface 352′ of tongue 280′ ofsegment 110′, and grooved shoulder surface 389′ of groove 380′ ofsegment 110′ becomes parallel and flush with outer surface 352 ofsegment 110.

As can be seen in FIG. 6, the annular nature of the gasket 150 defines acoupling void 410 within the gasket 150 that is adapted for certaindiameters of pipe elements. In practice, when pipe elements areintroduced within the gasket 150, they are placed inside the couplingvoid 410. Also seen in FIG. 6, a central axis of each of the bolts 120a,b is parallel to the vertical axis 425 such that heads 612 a,b of thebolts 120 a,b sit at an angle with the top surfaces 314, 316. Inalternative embodiments, the bolts 120 a,b may be angled with respect tothe vertical axis 425 such that heads of the bolts 120 a,b sit flushagainst the top surfaces 314,364. In the current embodiment, the gasket150 sits within the segments 110,110′. Each of the sealing surfaces 526a,b of the gasket 150 has the same cylindrical profile and the sameradius as the contact surfaces 262 a,b,a′,b′. In alternativeembodiments, the sealing surfaces 526 a,b of the gasket 150 may have asmaller or a larger radius than the contact surfaces 262 a,b,a′,b′. Inmany embodiments, sealing surfaces 526 a,b are in contact with the outersurfaces of the pipe elements before the tightening elements (bolts 120a,b and nuts 125 a,b) are engaged. In those embodiments, furthercompression of the gasket 150 will not necessarily produce a moreeffective seal. However, in other embodiments, it may be necessary forthe segments 110,110′ to compress the gasket 150 to effectuate a usefulseal against the outer surface of the pipe elements. In manyembodiments, sealing surfaces 532 a,b are positioned in contact with orslightly above contact with the pipe elements. In those embodiments,deformation of the gasket 150 is necessary to seal the sealing surfaces532 a,b against the pipe elements. In some embodiments, however, sealingsurfaces 532 a,b are in sufficient engagement with the pipe elementsprior to engagement of the tightening elements (bolts 120 a,b and nuts125 a,b) so that further tightening does not necessarily effectuate abetter seal.

Upon compression of the gasket 150 by the segments 110,110′, the gasket150 will most naturally deform from about circular in shape to an oblongshape. In most applications, compression by the segments 110,110′ on thegasket 150 will compress the gasket along the vertical axis 425, but thegasket 150 will tend to extend along the horizontal axis 420. Thisoccurs particularly because the segments 110,110′ first contact the pipeelements—and, thus, first compress the gasket 150—at a point central tothe segments 110,110′. As shown in FIGS. 4 and 6, the tongues 280,280′of the segments 110,110′ extend beyond the horizontal axis 420, therebypreventing the annular deformation of the gasket 150. Deformation of thegasket 150 is properly directed to the deformation groove 517 by thetongue 280 and groove 380 configuration of the coupling 100. Therestraint against oblong deformation provided by the tongues 280,280′promotes more uniform compression of the gasket 150 against the pipeelements, thereby providing a more reliable seal.

Tightening of the tightening elements (bolts 120 a,b and nuts 125 a,b)seats the gasket 150 against the pipe elements. When the segments110,110′ are properly deformed and the gasket 150 is properly seated,the coupling 100 restrains the pipe elements from pullout because thecontacting portion 292 a,b,a′,b′ (not shown in FIG. 6) of each segment110,110′ is seated inside at least one groove of at least one pipeelement. The gasket 150 is compressed in sealed engagement with the pipeelements. In some embodiments, the sealing members 557 a,b may bereplaced by a single sealing member that extends between the two pipes.Such deformation allows heads 612 a,b of the bolts 120 a,b to seat flushagainst the top surfaces 314,364 of segment 110 while nuts 125 a,b seatflush against the top surfaces 314′,364′ of segment 110′.

When properly seated, media (such as water, gas, or other fluid) may beallowed to flow through the pipe elements. The gasket 150 seals suchmedia in at least one of two ways. If the gasket 150 is compressed sothat sealing surfaces 532 a,b of the sealing members 557 a,b areproperly seated against the outside of the pipe elements, such sealinginteraction may be sufficient to contain the media inside the pipeelements without breaching the joint. In some applications, such sealingengagement may be impossible to attain, or the pressure of media withinthe pipe elements may be too great for such a sealing engagement toeffectuate a proper seal. In such applications, media may travel pastthe sealing members 557 a,b and into the gasket channels 540 a,b.

If media passes into the gasket channels 540 a,b, there are twosafeholds against leakage. First, in many applications, sealing surfaces526 a,b are in sealing engagement with the pipe elements prior tocompression of the gasket 150 by the segments 110,110′, and furthercompression of the gasket 150 enhances such sealing engagement. In otherapplications, sealing engagement of the gasket 150 with the pipeelements is achieved by compression of the gasket 150 by the segments110,110′. Second, if media passes into the gasket channels 540 a,b, itis assumed that such media is of a higher pressure than atmospheric. Assuch, the higher pressure in the gasket channels 540 a,b further forcesthe sealing ridges 525 a,b against the pipe elements. The higherpressure results in an even more effective seal by using the pressure ofthe media inside the pipe elements to effectuate a more complete seal.If liquid media is found in the pipe, such liquid may provide additionalair-tight seal to further aid the engagement of the gasket 150 with thepipe elements. In some embodiments, gas-proofing grease may be appliedto the contact surfaces 526 a,b and 532 a,b to aid in sealing. In manyembodiments, grease is unnecessary.

In the current embodiment, the coupling 100 is assembled in theuntightened position of FIG. 6 before use. In other embodiments, thecoupling 100 may be assembled in various pieces as part of the method ofuse.

The coupling 100 in FIG. 7 is shown tightened and deformed around a pairof pipe elements 710 b,a (710 a not shown in FIG. 7). The segments110,110′ in the current view are fully deformed in the currentembodiment, and contact surfaces 262 b,a′ touch a groove surface 714 b,a(714 a not shown in FIG. 7), which is the outer surface of the pipeelement 710 within the groove 720 b,a (not shown in FIG. 7). Contactsurface 262 a of segment 110 and contact surface 262 b′ of segment 110′are not shown in FIG. 7 because they are obstructed by the view. Asdescribed above, in some embodiments, the shoulder surfaces 296a,b,a′,b′ may contact an outermost surface of each pipe element 710 a,boutside of the groove 720 b,a (not shown in FIG. 7), and the contactsurfaces 262 a,b,a′,b′ may never contact the groove surface 714 a,b ofeach pipe element 710 a,b within each groove 720 a,b. In otherembodiments, the contact surfaces 262 a,b,a′,b′ contact the groovesurfaces 714 a,b.

When the segments 110,110′ travel toward each other and deform under thetightening of the tightening elements (nuts 120 a,b and bolts 125 a,b),the gasket 150 is deformed in accord therewith. In some embodiments, arigid or semi-rigid gasket 150 may be included. The process foraccommodating such a material may be altered from that described herein.The gasket 150 includes the deformation groove 517 to allow a place formaterial to go upon deformation of the gasket 150.

Installation of the coupling 100 on the pair of pipe elements 710 a,b isillustrated in FIGS. 8A-8E. For the current embodiment, the coupling 100is introduced to a pair of pipe elements 710 a,b in the preassembled butuntightened position of FIG. 6. Each pipe element 710 a,b may include atleast one groove 720 a,b for alignment with contact surfaces 262a,b,a′,b′. In the currently described method, the coupling 100 isaligned with an end 725 a of the first pipe element 710 a as shown inFIG. 8A. The coupling 100 is installed by placing the end 725 a of thefirst pipe element 710 a in the coupling void 410 and forcing thecoupling 100 onto the first pipe element 710 a as shown in FIG. 8B. Asseen in FIG. 8B, sealing surfaces 526 a,b and sealing surfaces 532 a,bare a small distance away from an outer surface 715 a of the first pipeelement 710 a, although the sealing surfaces 526 a,b and 532 a,b maycontact the outer surface 715 a in some embodiments. In thecurrently-described method, the entire coupling 100 is forced beyond thegroove 720 a of the first pipe element 710 a so that the contactsurfaces 262 b,b′ have passed the groove 720 a. In some embodiments, itmay not be necessary to force the entire coupling 100 beyond the groove720 a. As seen in FIG. 8C, the second pipe element 710 b having an end725 b is introduced in end-facing relationship to the end 725 a of thefirst pipe element 710 a. In the current embodiment, the pipe elements710 a,b are approximately the same diameter, although non-uniformdiameter pipe elements may be joined in various embodiments. In thecurrent embodiment, each pipe element 710 a,b has ends 725 a,b that areflared slightly. Grooves 720 a,b can be formed in one of two ways:rolled or machined. If the grooves 720 a,b are machined, the pipeelements 710 a,b are unlikely to have flares on the ends 725 a,b asshown. However, if the grooves 720 a,b are rolled, the pipe elements 710a,b are more likely to have flares on the ends 725 a,b. As such, thecoupling 100 of the current embodiment is designed to accommodate thepotential flaring of ends 725 a,b. The coupling 100 is sized to fit overthe largest possible flare of the ends 725 a,b in the current embodimentbased on standard tolerancing for creating the grooves 720 a,b.

When the second pipe element 710 b is about aligned with the first pipeelement 710 a, the coupling 100 is moved so that the gasket 150 isaligned on outer surfaces 715 a,b over the ends 725 a,b of the pipeelements 710 a,b and with the contact surfaces 262 a,b,a′,b′ alignedwith the grooves 720 a,b, as shown in FIG. 8D. As seen in FIG. 8E, whenthe segments 110,110′ are clamped down, the gasket 150 deforms intosealing engagement the outer surfaces 715 a,b of the pipe elements 710a,b and the contact surfaces 262 a,b,a′,b′ sit within the grooves 720a,b and touch groove surfaces 714 a,b. In various embodiments, thecontact surfaces 262 a,b,a′b′ may not touch groove surfaces 714 a,b uponclamping down the segments 110,100′.

Several features of the gasket 150 ease installation as described.Friction can cause installation of rubber gaskets to bind against outersurfaces 715 a,b of pipe elements 710 a,b. With reference to FIG. 3,FIG. 5, FIG. 6, and the method previously described with FIGS. 8A-8E,axially outer drafted edges 522 a,b and axially inner drafted edges 527a,b are both drafted to ease the pipe elements 710 into the couplingvoid 410. Axially outer drafted edges 522 a,b and axially inner draftededges 527 a,b also help to prevent rollover of the sealing ridges 525a,b of the gasket 150 during sliding on and off, as the drafted profilesare less likely to bind against the outer surfaces 715 a,b of the pipeelements 710 a,b. Additionally, contact portions 555 a,b aresubstantially parallel to the outer surface 715 a,b of the pipe elements710 a,b even when the gasket 150 is not seated on a pipe elements 710a,b. Additionally, the configuration of the center rib 530 with respectto the sealing ribs 527 a,b, as discussed above with reference to FIG.5, prevents the center rib 530 from obstructing the installation of thecoupling 100 by providing limiting contact between the center rib 530and the outer surface 715 a,b of pipe elements 710 a,b beforedeformation of the gasket 150. When the segments 110,110′ are clampeddown, the gasket 150 deforms, and the center rib 530 contacts the outersurface 715 a,b of pipe elements 710 a,b. This configuration allows thegasket 150 to slide onto the pipe elements 710 a,b without biasing thesliding in one direction and prevents binding of the sealing ridges 525a,b during installation. These features prevent the gasket 150 fromrolling over when the coupling 100 is installed on the pipe elements 710a,b and allows the gasket 150 to be properly placed over the jointbetween the pipe elements 710 a,b for proper sealing, among otheradvantages. When the gasket 150 is properly aligned over the joint, eachof the sealing members 557 a,b may contact the outer surface 715 a,b ofone pipe element 710 a,b or may be aligned above the surface 710 a,b ofthe pipe elements 715 a,b. However, the alignment of the sealing members557 a,b is not critical to effectuate a seal of the joint.

When the coupling 100 is aligned on the joint of the pipe elements 710a,b, the tightening elements are used to draw the segments 110,110′together. In the current embodiment, this takes the form of nuts 125 a,btightening down on bolts 120 a,b to compress the fastener pads 130a,b,a′,b′ toward each other. In some embodiments, the coupling 100 isrigid and includes no deflection of the segments 110,110′. In thecurrent embodiment, the engagement of the tightening elements (bolts 120a,b and nuts 125 a,b) first cause the segments 110,110′ to travel towardeach other. When the segments 110,110′ contact the pipe elements 710a,b, the segments 110,110′ deform (deflection) until each segment110,110′ is in the desired engagement with the pipe elements 710 a,b.The deformation of the segments 110,110′ can be seen by comparing FIGS.6 and 7. The contact surfaces 262 a,b,a′,b′ contact groove surfaces 714a,b of the grooves 720 a,b in the pipe elements, at which time thesegments 110,110′ begin deflection. In some embodiments, shouldersurfaces 296 a,b,a′,b′ (refer to FIG. 4 for the location of shouldersurfaces 296 a,b,a′,b′) contact the outer surface of the pipe elementssuch that the contact surfaces 262 a,b,a′,b′ never contact the groovesurfaces 714 a,b.

As can be seen in FIG. 7, the segments 110,110′ may deflect so thatbottom surfaces 362,362′ are in contact with bottom surfaces 312′,312,respectively, in some embodiments. This configuration need not bepresent in all embodiments. In some embodiments, the mating surfaces355,355′ will contact mating surfaces 395′,395, respectively, before thebottom surfaces 362,362′ contact bottom surfaces 312′,312, respectively.In some embodiments, bottom surfaces 362,362′ will contact bottomsurfaces 312′,312 before mating surfaces 355,355′ contact matingsurfaces 395′,395, respectively. Because of the deflection anddeformation of the segments 110,110′, the angles 415,416,417,418, aspointed out in FIG. 4 (angles 415′,416′,417′,418′ not shown), arereduced as the top surfaces 314,314′ and 364,364′ and the bottomsurfaces 312,312′ and 362,362′ approach a position parallel with thehorizontal axis 420. As shown, mating surfaces 355,355′ are in contactwith mating surfaces 395′,395, respectively, as well.

Seen in the cross-sectional view of FIG. 9, each bolt 120 a,b (b notshown in FIG. 9) includes a head 612 a,b (b not shown in FIG. 9), athreaded portion 810 a,b (b not shown in FIG. 9), a shank portion 815a,b (b not shown in FIG. 9), and a collar portion 820 a,b (b not shownin FIG. 9). Combined together, each threaded portion 810 a,b, shankportion 815 a,b, and collar portion 820 a,b is termed the shaft portion.Each shaft portion may omit any combination of the threaded portion 810,shank portion 815, and collar portion 820 in various embodiments. Thenuts 125 a,b (b not shown in FIG. 9) engage the bolts 120 a,b (b notshown in FIG. 9) along part of the threaded portion 810 a,b. Tighteningof the nuts 125 a,b compresses the fastener pads 130 a,b,a′,b′ anddeforms the segments 110,110′ to conform to the shape of the pipeelements, as previously described.

As previously described, when the coupling 100 is installed onto pipeelements, the assembled and untightened coupling 100 is installed overthe edge of the first pipe element 710 a until it passes completely overany groove 720 a in the first pipe element 710 a after which the secondpipe element 710 b is placed end-facing to the first pipe element 710 a.The coupling 100 is then slid into position straddling the first andsecond pipe elements 710 a,b. Although (as previously described) it iscommon for gaskets to bind during such installation, it is also possiblefor friction to cause rocking of the segments 110,110′ not only againstany gasket but also against the exterior of the pipe elements 710 a,b.If a leading edge of one segment 110,110′ catches against the exteriorof the pipe element 710 a,b, the segments 110,110′ have a tendency torock with respect to each other. Rocking of segments 110,110′ can causeadditional binding of the gasket 150, making installation of thecoupling 100 difficult and potentially damaging to components of thecoupling 100, including the gasket 150.

The shape of the fastener hole 132 a (see FIG. 2) includes an axiallength 233 (axial length 237 of fastener hole 132 b not shown) thattends to prevent such rocking of the segments 110. For the fasteners ofthe current embodiment, each of the heads 612 a,b, threaded portions 810a,b, and shank portions 815 a,b are symmetrical about the center of thebolt 120 a,b, respectively. The shank portions 815 a,b are cylindrical,the threaded portions 810 a,b are cylindrical except that each hasthreading along its outermost edge, and the heads 612 a,b arecross-sectionally circular at cross-sections taken orthogonal to thecenter axis. However, the collar portions 820 a,b are not cylindricalbut instead include a profile approximating that of the fastener holes132 a,b as measured at the top surfaces 364,314. Each collar portion 820a,b includes an axial length 830 a,b that is about the same as thediameter of the shank portions 815 a,b. The collar portions 820 a,b alsoinclude a transverse length (not shown) that is proportionally largerthan the axial length 830 a,b. The axial length 830 a,b of each collarportion 820 a,b may be smaller than the axial length 233,237 of eachfastener hole 132 a,b, the transverse length of each collar portion 820a,b may be smaller than the transverse length 243,247 of each fastenerhole 132 a,b, and the axial length 233,237 of each fastener hole 132 a,bis smaller than the transverse length 830 a,b of each collar portion 820a,b.

The arrangement of each collar portion 820 a,b engages the fastener hole132 a,b in assembly and retains the bolt 120 in a fixed arrangement withrespect to the segment 110 in each fastener hole 132 a,b. This allows auser to tighten the nuts 125 a,b without need to restrain the bolts 120a,b, as the collar portions 820 a,b retain the bolts 120 a,b throughinteraction with the fastener holes 132 a,b. This result occurs becausethe axial length 233,237 of each fastener hole 132 a,b is smaller thanthe transverse length 830 a,b of each collar portion 820 a,b. Such anarrangement would result even if the orientation of the fastener holes132 a,b were at a different angle.

However, the arrangement as displayed also prevents the rocking of thesegments 110,110′ by keeping the shank portions 815 a,b, the collarportions 820 a,b, and the threaded portions 810 a,b in close proximityto the inner surfaces 335 a,b,a′,b′ of the fastener holes 132 a,b,a′,b′.Should one of the segments 110,110′ begin a rocking motion, at least oneof the inner surfaces 335 a,b,a′,b′ will contact at least one of thebolts 120 a,b along at least one of the collar portions 820 a,b, theshank portions 815 a,b, and the threaded portions 810 a,b therebyproviding a mechanical stop to prevent further rotation of the segments110,110′ with respect to the bolts 120 a,b and, thereby, with respect tothe other segment 110′,110.

Although all sides of the fastener holes 132 a,b,a′,b′ are shown asdrafted in the current embodiment, some sides may be drafted or may beparallel in various embodiments. For example, in the current embodiment,fastener holes 132 a,b,a′,b′ are drafted because the segments 110,110′are cast. However, if fastener holes 132 a,b,a′,b′ were machined, itwould not be necessary to draft the fastener holes 132 a,b,a′,b′.

As seen in FIG. 10, each pair of contact surfaces 262 a,b and 262 a′,b′(262 b and 262 b′ shown in FIGS. 10 and 11) defines a predeformationradius 1001,1001′. Likewise, each pipe element 710 a,b defines a radius1002 a,b. In the current embodiment, when the coupling 100 is in theuntightened position, the predeformation radii 1001,1001′ of each pairof contact surfaces 262 a,b and 262 a′,b′, respectively, is greater thanthe radii 1002 a,b of the pipe elements 710 a,b. Groove radii 1003 a,bare also shown on the pipe elements 710 a,b, respectively. Because thepredeformation radii 1001,1001′ are larger than the radii 1002 a,b, thecoupling 100 can be more easily maneuvered over each pipe element 710a,b as described more thoroughly with reference to FIGS. 8A-8E. Havinglarger predeformation radii 1001,1001′ than radii 1002 a,b allows thecoupling 100 to be slid onto the pipe elements 710 a,b as a preassembledunit. As described above, once the coupling 100 is aligned over the pipeelements 710 a,b, no further assembly of the coupling 100 is required.Instead, the user need only tighten the nuts 125 a,b on the bolts 120a,b to secure the coupling 100 in sealing engagement with the pipeelements 710 a,b.

As seen in FIG. 11, once the nuts 125 a,b are tightened onto the bolts120 a,b, each segment 110,110′ of the coupling 100 deforms in conformitywith the grooves 720 a,b. Once deformed, a postdeformation radius1101,1101′ is defined by each pair of contact surfaces 262 a,b and 262a′,b′ (262 b and 262 b′ shown in FIGS. 10 and 11), respectively. In thecurrent embodiment, each postdeformation radius 1101,1101′ is equal tothe groove radii 1003 a,b because the contact surfaces 262 a,b,a′,b′contact the groove surfaces 714 a,b. In embodiments where the contactsurfaces 262 a,b,a′,b′ do not contact the groove surfaces 714 a,b, thepostdeformation radii 1101,1101′ may be larger than the groove radii1003 a,b. Although not required in all embodiments, the postdeformationradii 1101,1101′ will likely be smaller than the radii 1002 a,b even ifthe postdeformation radii 1101,1101′ is larger than the groove radii1003 a,b.

This assembly configuration represents one of many possible assemblyconfigurations. One skilled in the art will understand obviousvariations of this assembly configuration are included within thisdisclosure, including variations of steps, combinations of steps, anddissections of steps, among others. Where materials are chosen for theelements of this assembly—particularly, rubber, metal, and castiron—similar material choices may also be used and would be obvious toone in the art. As previously disclosed, the gasket 150 may be made ofrubber, plastic, cork, wood, metal, ceramic, polymer, elastomer, rosin,foam, any combination of the foregoing materials, or any materialsuitable for sealing two pipe elements joined in end-to-endrelationship. The segments 110,110′ may be made of cast iron, steel,aluminum, titanium, copper, brass, various plastics, polymers, resins,or any material of sufficient strength to withstand the tightening loadof the fasteners.

It should be emphasized that the embodiments described herein are merelypossible examples of implementations, merely set forth for a clearunderstanding of the principles of the present disclosure. Manyvariations and modifications may be made to the described embodiment(s)without departing substantially from the spirit and principles of thepresent disclosure. Further, the scope of the present disclosure isintended to cover any and all combinations and sub-combinations of allelements, features, and aspects discussed above. All such modificationsand variations are intended to be included herein within the scope ofthe present disclosure, and all possible claims to individual aspects orcombinations of elements or steps are intended to be supported by thepresent disclosure.

One should note that conditional language, such as, among others, “can,”“could,” “might,” or “may,” unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain embodiments include, while other embodiments donot include, certain features, elements and/or steps. Thus, suchconditional language is not generally intended to imply that features,elements and/or steps are in any way required for one or more particularembodiments or that one or more particular embodiments necessarilyinclude logic for deciding, with or without user input or prompting,whether these features, elements and/or steps are included or are to beperformed in any particular embodiment.

Various implementations described in the present disclosure may includeadditional systems, methods, features, and advantages, which may notnecessarily be expressly disclosed herein but will be apparent to one ofordinary skill in the art upon examination of the following detaileddescription and accompanying drawings. It is intended that all suchsystems, methods, features, and advantages be included within thepresent disclosure and protected by the accompanying claims.

That which is claimed is:
 1. A coupling comprising: an annular gasket,the annular gasket including at least one sealing surface directedradially inwardly and an outer surface directed radially outwardly; atleast one segment, each segment being approximately semi-circular andincluding at least one inner surface, at least one outer surface, afirst end, and a second end, each segment including a fastener padprotruding proximate to each end, each fastener pad defining a fastenerhole, the first end including a first shoulder and a tongue and thesecond end including a second shoulder and a groove, the first shoulderincluding a first bottom surface and the second shoulder including asecond bottom surface, the first bottom surface offset from a horizontalaxis of the coupling in a first direction with the coupling in anassembled and tightened condition, the second bottom surface offset fromthe horizontal axis in a second direction opposite the first directionwith the coupling in the assembled and tightened condition, the firstbottom surface non-coplanar with the second bottom surface with thecoupling in the assembled and tightened condition, each tongue includingan inner surface and a leading edge and protruding circumferentiallyfrom each first end, the leading edge including a mating surfaceparallel to an axial direction of the coupling, the inner surface ofeach tongue adapted to contact the outer surface of the annular gasket,each groove defined circumferentially in each second end, each groovesized to accept the tongue of a one of the at least one segment; and atleast one fastener, wherein at least one portion of a shaft portion ofthe fastener is sized to engage at least one fastener hole in at leastone segment.
 2. The coupling of claim 1, wherein at least one tongueincludes a leading edge.
 3. The coupling of claim 2, wherein eachleading edge includes a mating surface.
 4. The coupling of claim 3,wherein the groove includes a mating surface.
 5. The coupling of claim4, wherein the mating surface of the groove contacts the mating surfaceof the tongue.
 6. The coupling of claim 1, wherein each segment includestwo contact surfaces.
 7. The coupling of claim 1, wherein the annulargasket includes at least one center rib and at least two sealing ridges.8. The coupling of claim 7, wherein the center rib includes two sealingsurfaces and wherein each sealing ridge includes a sealing surface. 9.The coupling of claim 8, wherein a central groove separates the twosealing surfaces of the center rib.
 10. The coupling of claim 7, whereineach sealing ridge is disposed between an axially inner drafted edge andan axially outer drafted edge.
 11. The coupling of claim 7, wherein thesealing surfaces of the sealing ridges are substantially parallel. 12.The coupling of claim 1, wherein the gasket includes at least two gasketchannels.
 13. The coupling of claim 1, wherein each fastener includes acollar portion and wherein each collar portion includes an axialdimension and a transverse dimension, and wherein each axial dimensionis smaller than each transverse dimension.
 14. The coupling of claim 13,wherein each axial dimension of each collar portion is smaller than eachaxial dimension of each fastener hole, wherein each transverse dimensionof each collar portion is smaller than each transverse dimension of eachfastener hole, and wherein each axial dimension of each fastener hole issmaller than each transverse dimension of each collar portion.
 15. Thecoupling of claim 1, wherein each tongue extends beyond the horizontalaxis of the coupling.
 16. A coupling comprising: an annular gasket, theannular gasket including at least one sealing surface directed radiallyinwardly and an outer surface directed radially outwardly; at least onesegment, each segment being approximately semi-circular and including atleast one inner surface, at least one outer surface, a first end and asecond end, each segment including a fastener pad protruding proximateto each end, each fastener pad defining a fastener hole, the first endincluding a first shoulder and a tongue and the second end including asecond shoulder and a groove, the first shoulder including a firstbottom surface and a first bottom angle and the second shoulderincluding a second bottom surface, the first bottom surface offset froma horizontal axis of the coupling in a first direction with the couplingin an assembled and tightened condition, the second bottom surfaceoffset from the horizontal axis in a second direction opposite the firstdirection with the coupling in the assembled and tightened condition,the first bottom surface non-coplanar with the second bottom surfacewith the coupling in the assembled and tightened condition, each tongueincluding an inner surface and a tip angle and protrudingcircumferentially from each first end, the tip angle and the firstbottom angle measured from a radial direction, the tip angle of thetongue of the first end being greater than the first bottom angle of theshoulder of the first end, each tongue and each groove symmetrical abouta plane oriented perpendicular to a longitudinal axis of the couplingsegment, each groove defined circumferentially in each second end, eachgroove sized to accept the tongue of a one of the at least one segment;and at least one fastener, wherein at least one portion of a shaftportion of the fastener is sized to engage at least one fastener hole inat least one segment.
 17. The coupling of claim 16, wherein each tongueextends beyond the horizontal axis of the coupling.
 18. A couplingcomprising: an annular gasket, the annular gasket including at least onesealing surface directed radially inwardly and an outer surface directedradially outwardly; at least one segment, each segment beingapproximately semi-circular and including at least one inner surface, atleast one outer surface, a first end and a second end, each segmentincluding a fastener pad protruding proximate to each end, each fastenerpad defining a fastener hole, the first end including a first shoulderand a tongue and the second end including a second shoulder and agroove, each tongue including an inner surface and protrudingcircumferentially from each first end, the inner surface of each tongueintersecting the inner surface of each segment, the first shoulderincluding a first bottom surface and the second shoulder including asecond bottom surface, the first bottom surface offset from a horizontalaxis of the coupling in a first direction with the coupling in anassembled and tightened condition, the second bottom surface offset fromthe horizontal axis in a second direction opposite the first directionwith the coupling in the assembled and tightened condition, the firstbottom surface non-coplanar with the second bottom surface with thecoupling in the assembled and tightened condition, each groove definedcircumferentially in each second end, each groove sized to accept thetongue of a one of the at least one segment; and at least one fastener,wherein at least one portion of a shaft portion of the fastener is sizedto engage at least one fastener hole in at least one segment.
 19. Thecoupling of claim 18, wherein each tongue extends beyond the horizontalaxis of the coupling.